Hydroperoxidation process



United 'tates 2,868,842 Patented Jan. 13, 1959 ice 7 tetrahydronaphthalene, 1,1,4 tri sec amyl 1,2,3,4-

Mich., and Alfred J. Kolka, Pittsburgh, Pa., assignors to Ethyl Corporation, New York, N. Y., a corporation of Delaware No Drawing. Original application March 1, 1954, Seria No. 413,482. Divided and this application February 28, 1958, Serial No. 718,117

3 Claims. 01'. 260-4610) This invention relates to new compositions of matter and methods of making the same. More particularly, the invention refers to a new class of compounds compris- Theproduct may also ing 1,4-dialkyl 1,2,3,4-tetrahydronaphthalenes and 1,1,4-

trialkyll,2,3,4-tetrahydronaphthalenes, wherein said 1 and 4 positions are on the saturated carbon atoms in the'tetralin ring which carbon atoms are alpha to a doubly bonded nuclear carbon atom and wherein each alkyl group contains at least two carbon atoms. This is a division of application Serial No. 413,482, filed March 1, 1954, and now abandoned.

Cyclodehydration of aromatic alcohols has been employed to make substituted Tetralin (substituted 1,2,3,4- tetrahyd'ronaphthalene), having alkyl groups in'the 1 and 2 positions. However, 1,4-dialkylor 1,1,4-trialkyl- 1,2,3,4-tetrahydronaphthalenes having two or more carbon atoms in each alkyl group have not been synthesized in the past. ,Itis an object, therefore, ofthis invention to provide as'new compositions of-matter 1,4-dialkyl-1,2-,3,4- tetrahydronaphthalenes and 1,1,4-trialkyl-1,2,3,4 tetrahydronaphthalenes, wherein each alkyl group contains at least two carbon atoms, having new and unexpected properties. It is a' further object of this invention to provide as new compositions of matter, 1,4-dialkyl- 1,2,3 ,4-tetrahydronaphthalenes and 1,1,4-trialkyl-1,2,3 ,4- tetrahydronaphthalenes in which each of the alkyl groups contain from two to about eighteen carbon atoms. It is also an object of this invention to provide methods for the manufacture of these new compositions of matter. Another object is to provide new compounds useful in 'the synthesis of chemicals which find uses as monomers, plasticizers, polymer and resin components, oxygen acceptors, and other uses. The above and other objects of our invention are provided by the class of compounds comprising Tetralins (1,2,3,4-tetrahydronaphthalenes), containing alkyl groups in the 1 and 4 positions and wherein not more than 3 hydrogensin the 1 and 4 positions are replaced by said alkyl groups and wherein each alkyl group contains not less than two carbon atoms. More particularly, the objects of our invention are accomplished by 1,4- dialkyl-1,2,3,4-tetrahydronaphthalenes and 1,1,4-trialkyll,2,3,4-tetrahydronaphthalenes in which the number of carbon atoms in an alkyl group is from two to about eighteen. Y

Non-limiting examples of the compounds of this invention are 1,4-diethyl-1,2,3,4-tetrahydronaphthalene and 1,1,4-triethyl-1,2,3,4-tetrahydronaphthalene, 1,4-diisopropyl 1,2,3,4 tetrahydronaphthalene, 1,1,4 triisopropyl- 1,2,3,4 tetrahydronaphthalene, 1,4 di sec butyl- 1,2,3,4 tetrahydronaphthalene, 1,1,4 tri sec butyl- 1,2,3,4 tetrahydronaphthalene, 1,4 di tert butyl- 1,2,3,4 tetrahydronaphthalene, 1,1,4 tri tert butyl- 1,2,3,4 tetrahydronaphthalene, 1,4 di-sec-amyl-1,2,3,4-

' 4 sec butyl 1,2,3,4

tetrahydronaphthalene, .1,4,- .di; tert r amyl 1,2,3,4 tetrahydronaphthalene, 1,4 di sec octyl 1,2,3,4 tetrahydronaphthalene, 1,4, bis(ethylhexyl) 1,2,3,4-tetrahydronaphthalene, 1,4 di sec dodecyl-1,2,3,4-tetrahydro naphthalene, 1,4 di tert dodecyl '-"1-,2,3,4' tetrahydronaphthalene, 1,4 bis(1 methylundecy1)-1',2 ,3',4 tetrahydronaphthalene, 1,4 bis(1 -..methylpentadecyl)1,2,3,4- tetrahydronaphthalene, 1,4 bis(1 methylhexadecyl) 1,2,3,4 tetrahydronaphthalene, 1,4-bis(l methylheptadecyl)1,2,3,4 tetrahydronaphthalene, 1,4 di, sec. octatetrahydronaphthalene, 1,4 di tert tetrahydronaphthalene, and the like. have more than one kind of alkyl group in the same molecule as for example, l-ethyl-4- isopropyl 1,2,3,4 tetrahydronaphthalene, 1,4 diethyl- 1 isopropyl 1,2,3,4 tetrahydronaphthalene, 1,4 ethyl- 1,4-diisopropyl 1,2,3,4 tetrahydronaphthalene, 1 ethyltetrahydronaphthalene, 1,4 ditetrahydronaphthalene,

- 1,2,3,4 tetrahydro- 1,2,3,4 tetrahydrododecyl 1,2,3,4-

decyl 1,2,3,4 octadecyl 1,2,3,4

ethyl 1 sec butyl 1,2,3,4 1-- ethyl 1,4 di sec butyl naphthalene, 1' ethyl 4 e dodecyl naphthalene, 1,4. diethyl 1 sec tetrahydronaphthalene, and the like.

The lower molecular welght compounds of our invention are clear, colorless liquids with a boiling point above 260 C; The boiling point increases with increase in molecular weight. The compounds of this invention are useful as oxygen acceptors, and in the preparation of monomers, plasticizers, polymer and resin components, polymerization initiators, etc.

The alkyltetralin compounds of this invention are obtained by a process comprising reacting tetralin with monoolefins in the presence of a catalyst.

As catalysts in our invention organo-alkali metal com.- pounds generally are acceptable. This includes organo compounds of sodium, potassium, lithium, cesium and rubidium. We prefer to use organo compounds of a1- kali metals of atomic weight higher than 7, particularly sodium and potassium. We prefer as catalyst to use hydrocarbo-alkali metal compounds. Illustrative examples include alkyl-alkali metal compounds such as amyl sodium, butyl sodium, hexyl potassium, and the like;

aryl-alkali metal compounds such as phenyl sodium, p-tolyl potassium, phenyl lithium, and the like; and alkylaryl-alkali metal compounds such as tetralin sodium, benzyl potassium, benzyl sodium, cumyl sodium, and the like. Mixtures of organo-alkali compounds can be used with equally good results. 7

One of the uses of the new compounds of this invention is their utility to take up oxygen and form hydroperoxide products. It has also been found, that the 1,4-

diand 1,1,4-trialkyl-1,2,3,4-tetrahydronaphthalenes, in

which each alkyl group contains at least two carbon atoms, take up oxygen at a much faster rate than corresponding l-alkyl-l,2,3,4-tetrahydronaphthalenes. To illustrate the variation in the rate of oxidation to the hydroperoxidized products of 1,2,3,4=tetrahydronaphthalene and the various substituted 1,2,3,4-tetrahydronaphthalenes, oxygen was slowly passed through each of the compounds in question and samples were withdrawn at regular intervals of time and an analysis made in order to determine the amount of hydroperoxide product formed. Table I summarizes the results. In each case an emulsion of the compound in water formed with the aid of a minor amount of sodium stearate was kept at a temperature of C. while oxygen was slowly passed through. The rate of flow of oxygen was the same for each compound shown in the table.

It will be noted that l-ethyl-1,2,3,4-tetrahydronaphthalene yielded no hydroperoxide product at the end of three hours of oxidation while 1,4-diethyltetralin oxidized to an extent equivalent to 7.5% monohydroperoxide product of the 1,4-diethyl-1,2,3,4-tetrahydronaphthalene originally present in an equal interval of time under similar conditions. Furthermore, at the end of six hours of oxidation the l,4-diethyl-1,2,3,4-tetrahydronaphthalene had formed 180% more hydroperoxidized product than 1-ethyl 1,2,3,4-tetrahydronaphthalene. This illustrates the greatly enhanced and unexpected susceptibility of the 1,4-dialkyl-1,2,3,4-tetrahydronaphthalenes of this invention to oxidation or oxygen uptake. In comparing the rate of hydroperoxidation of 1,1,4 triethyl 1,2,3,4 tetrahydronaphthalene to that of l-ethyl-1,2,3,4-tetrahydronaphthalene, it is found, upon taking into consideration the fact that l-ethyl-1,2,3,4-tetrahydronaphthalene has three hydrogens on the carbon atoms alpha to the nuclear bond which is susceptible to hydroperoxidation while 1,1,4-triethyl-1,2,3,4-tetrahydronaphthalene has only one hydrogen on such alpha carbon atom, that the rate of hydroperoxidation of the latter is about twice as fast as that of l-ethyl-1,2,3,4-tetrahydronaphthalene. This further illustrates the unexpected oxygen accepting properties of the compounds of this invention.

It is seen, therefore, that one of the uses of the compounds of the present invention is in the role of oxygen acceptors. They can also be used in the synthesis of other products, such as 1,4-diethylnaphthalene, 1,4-dicarboxynaphthoic acid, 1,4-divinylnaphthalene, 1,4-dihydroxynaphthalene, and the like. The hydroperoxidized product obtained by the oxidation of 1,4-diethyl-1,2,3,4- tetrahydronaphthalene can be used to synthesize catechol. In each of these cases the product consists of but one isomer and thus eliminates the costly and time consuming steps often found necessary in order to separate the desired product from closely related isomers when using other processes. This illustrates the decided advantage of employing the compounds of our invention as starting materials in the synthesis of the above mentioned compounds.

In the commercial production of the compounds of our invention it is particularly attractive to conduct the process in a continuous manner. This can be done by a variety of techniques such as passing the reactants together with the catalyst, either substantially pure or admixed With an inert carrier, through a reaction zone. The product stream can be purified by distillation in a continuous fractionation column. The continuous method for the production of the compounds of our invention can be carried out either in a once through manner or with recycling of reactants and products. In continuous and batch modifications of our invention, the reactants can be diluted with inert gases such as propane, ethane, methane, nitrogen, helium, neon, and the like.

We claim:

1. A process for the hydroperoxidation of 1,2,3,4- tetrahydronaphthalene containing at least 2 ethyl groups in the 1 and 4' positions wherein not more than 3 hydrogens in said 1 and 4 positions are replaced by said ethyl groups, comprising passing oxygen through an emulsion of said 1,2,3,4-tetrahydronaphthalene compound in water.

2. A process for the hydroperoxidation of 1,2,3,4-tetrahydronaphthalene containing at least 2 ethyl groups in the 1 and 4 positions, wherein not more than 3 hydrogens in said 1 and 4 positions are replaced by said ethyl groups, comprising passing oxygen through an emulsion of said 1,2,3,4-tetrahydronaphthalene compound in water containing a minor amount of sodium stearate as an' emulsifying agent.

3. A process for the hydroperoxidation of 1,4-diethy1- 1,2,3,4-tetrahydronaphthalene comprising passing oxygen through an emulsion of said 1,2,3,4-tetrahydronaphthalene compound in water containing a minor amount of sodium stearate as an emulsifying agent.

References Cited in the file of this patent UNITED STATES PATENTS 2,797,249 Young June 25, 1957 2,807,650 Webster et al Sept. 24, 1957 OTHER REFERENCES Eglofi: Physical Constants of Hydrocarbons; vol. IV, p. 41. Pub. by Reinhold Pub. Corp., New York (1947).

Sisido et al.: Jour. Amer. Chem. Soc., vol. (1948), p. 1288.

Hock et al.: Ber. Deut. Chem., vol. 83 (1950), pp. 238-244. 

1. A PROCESS FOR THE HYDROPEROXIDATION OF 1,2,3,4TETRAHYDRONAPHTHALENE CONTAINING AT LEAST 2 ETHYL GROUPS IN THE 1 AND 4 POSITIONS WHEREIN NOT MORE THAN 3 HYDROGENS IN SAID 1 AND 4 POSITIONS ARE REPLACED BY SAID ETHYL GROUPS, COMPRISING PASSING OXYGEN THROUGH AN EMULSION OF SAID 1,2,3,4-TETRAHYDRONAPHTHALENE COMPOUND IN WATER. 